1. Field of the Invention
The present invention relates to apparatus and methods for preventing, regulating or stopping the escape of oil, gas or other fluid from wells or pipes.
2. Description of the Prior Art
As shown by recent events in the Gulf of Mexico, oil well blowouts are a serious threat to the environment, and can be very costly. Current blowout control devices can be unreliable. While there are numerous prior inventions of blowout control devices, none are equivalent to the present invention.
U.S. Pat. No. 1,543,456, issued on Jun. 23, 1925, to Robert Stirling, discloses an early blowout preventer, without the explosive charges or pistons of the instant invention.
U.S. Pat. No. 3,548,848, issued on Dec. 22, 1970, to Gerhardt C. Stichling, discloses explosive actuated valves, but does not disclose their use in a blowout control device, as in the instant invention.
U.S. Pat. No. 3,766,979, issued on Oct. 23, 1973, to John T. Petrick, discloses a well casing cutter and sealer, but does not disclose pistons moving the plates, as in the instant invention.
U.S. Pat. No. 3,980,094, issued on Sep. 14, 1976, to Fritz Schröder and Klaus Rössel, discloses a quick action slide valve with a sliding plate, but does not disclose the pistons moving the plates of the instant invention.
U.S. Pat. No. 4,215,749, issued on Aug. 5, 1980, to Roy R. Dare and Jeff L. Merten, discloses a gate valve for shearing workover lines to permit shutting a well, using a shear plate and pistons. The instant invention is distinguishable, in that in it the plates are explosively activated and/or retractable by gears.
U.S. Pat. No. 4,523,639, issued on Jun. 18, 1985, to Roland M. Howard, Jr., discloses ram-type blowout preventers, with a piston and a locking mechanism to hold the plate in the channel after the pipe has been cut, but does not disclose a flange to limit motion of the piston, as in the instant invention.
U.S. Pat. No. 4,619,284, issued on Oct. 28, 1986, to Jean-Jacques Delarue and Claude Ego, discloses a pyrotechnic valve that may either close an initially open pipe or open an initially closed pipe, but does not disclose its use in a blowout control device, as in the instant invention.
U.S. Pat. No. 5,012,854, issued on May 7, 1991, to John A. Bond, discloses a pressure release valve for a subsea blowout preventer that is hydraulically operated. The instant invention is distinguishable, in that in it the plates are explosively activated and/or retractable by gears.
U.S. Pat. No. 5,064,164, issued on Nov. 12, 1991, to Tri C. Le, discloses a blowout preventer with metal inserts resembling the plates in the instant invention, but does not disclose explosive actuation or movement of the plates by gears, as in the instant invention.
U.S. Pat. No. 5,156,212, issued on Oct. 20, 1992, to Thomas B. Bryant, discloses a method and system for controlling high pressure flow, such as in containment of oil and gas well fires, but does not disclose pistons whose movement is limited by flanges, as in the instant invention.
U.S. Pat. No. 5,735,502, issued on Apr. 7, 1998, to Bryce A. Levett and Mike C. Nicholson, discloses a blowout preventer with ram blocks resembling the plates in the instant invention, and is hydraulically actuated. The instant invention is distinguishable in that it has pistons whose movement is limited by flanges.
U.S. Pat. No. 6,354,568, issued on Mar. 12, 2002, to Alec Carruthers, discloses a sliding plate valve, but does not disclose pistons whose movement is limited by flanges, as in the instant invention.
U.S. Pat. No. 6,739,570, issued on May 25, 2004, to Hans-Paul Carlsen, discloses a valve element, which may be used for closing a channel in a blowout preventer, but does not disclose pistons whose movement is limited by flanges, as in the instant invention.
U.S. Pat. No. 7,243,713, issued on Jul. 17, 2007, to C. Steven Isaacks, discloses a shear/seal assembly for a ram-type blowout prevention system. The instant invention is distinguishable, in that it discloses plates that are explosively activated and/or retractable by gears.
U.S. Pat. No. 8,316,872, issued on Nov. 27, 2012, and pending U.S. patent application Ser. No. 13/685,957, filed on Nov. 27, 2012, both to Philip John Milanovich, the inventor and applicant herein, disclose blowout preventers using plates propelled by explosive charges. The instant invention is distinguishable, in that in it the plates are moved by pistons, whose movement is limited by flanges.
U.S. Patent Application Publication No 2009/0050828, published on Feb. 26, 2009, to Jeffrey Charles Edwards, discloses blowout preventers with a housing having a throughbore resembling the channel in the instant invention, which may be closed by a pair of opposed rams, but does not disclose limitation of movement by flanges, explosive actuation, or movement by gears, as in the instant invention.
British Patent No. 2 175 328, published on Nov. 26, 1986, to Richard Theodore Mitchell, discloses an oil well drilling apparatus, including a blowout preventer stack, without the use of explosive charges, or movement of the plates by pistons moved by gears, as in the instant invention.
Canadian Patent No. 2 506 828, published on Oct. 29, 2006, inventors Dean Foote and Scott Delbridge, discloses a blowout preventer with rams that are hydraulically rather than explosively actuated, or moved by pistons moved by gears, as in the instant invention.
Soviet Patent No. 1427057, published Sep. 30, 1988, inventors Y. U. A. Gavrilin, L. M. Torsunov and B. V. Venedictov, discloses a blowout preventer with a flat blocking gate.
None of the above inventions and patents, taken either singly or in combination, is seen to describe the instant invention as claimed.